Apparatus for reducing and concentrating ores.



No. 738,006. PATBNTED SEPT. 1, 190a.

' 0. B. DAWSON. I

APPARATUS FOR REDUCING AND OONGENTRATING ORES.

APPLICATION FILED MAR. 6, 1903.

I10 MODEL.

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UNITED STATES Patented September 1, 1903.

PATENT OFFICE.

OLIVER B. DAlVSON, OF CALDWELL, NEW JERSEY.

SPECIFICATION forming part of Letters Patent No. 738,006, dated September 1, 1903.

Application filed March 6, 1903.

T0 66 whom it TIT/y concern:

Be it known that I, OLIVER B. DAWSON, of Caldwell, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Reducing and Concentrating Ores; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The object of this invention is to provide an improved furnace for reducing and concentrating minerals in the ore, which under a continuous feed are first reduced and then concentrated and formed into globular masses, as shot or nuggets, in the ore-matrix, which maybe readily separated by crushing and screening.

A further object is to provide a furnace of this kind which will be extremely simple in construction and which may be controlled with but little labor and operated under an economy of fuel.

1 have found that the temperature of incandescene is that at which hydrogen will be most active in combining with those elements originally united with the metals that compose the minerals. It is the temperature of extreme chemical activity of hydrogen when brought in contact with mineral salts.

According to my invention the mineralbearing rock, of small size, is fed into a chamber heated to the temperature of incandescence and through which pass the products of combustion of the heating medium mingling with a reducing-gas supplied to the reduction-chamber and serving to reduce mineral in the ore or matrix into a metallic spongy condition, which upon leaving the reduction-chamber and while still within the furnace is finally concentrated into metallic globular formations by heat suflicieut to fuse the matrix or gangue.

The invention will be hereinafter fully set forth, and particularly pointed out in the claims. 7

In the accompanying drawings the figure is a vertical longitudinal sectional view of a furnace constructed in accordance with my invention.

Referring to the drawings, 1 designates a furnace casing of approximately airtight Serial No. 146,602. (No model.)

construction, 2 the smoke-stack, and 3 an orehopper.

4 is the chamber through which the ore passes and wherein the mineral contained therein is reduced into a spongy condition. This chamber may be made of cast-iron of about three-fourths of an inch in thickness, or, if desired, it may be lined'with short sections of well-burned silicious fire-clay tubes held in place with pasty fire-clay cement. It is preferably of cylindrical formation and is set on an incline, so that the ore will in the rotation of the chamber pass therethrough by gravity, the discharge-spout 5 of the hopper opening into the upper end of such chamber. At its lower end the chamber has its bearings in the inner wall of the smoke- A stack, into which latter such end opens, and in line therewith in the outer wall of the stack is a peep-hole or twyer 6. Extending longitudinally through the chamber is a perforated pipe 7 for supplying a reducing-gas to the ores. This pipe is connected to the chamber by spiders 8, and in its bearing in the furnace-wall, through which it is extended, forms the axial support for the other or upper end of the chamber, thereby leaving such end of the latter open to the combustion-chamber J of the furnace. A flanged plate 10, extended beneath the upper endof the chamber, prevents the ore from falling into the combustion-chamber of the furnace. The reduction-chamber is rotated by belting or gearing 12, engaging the projecting portion of the pipe 7, such pipe forming a shaft for the chamber. At its outer end pipe 7is con nected to a tank 13, containing a reducinggas, such as hydrogen or water gas, which latter when the valve 14 of such pipe is open passes into the ore-heating chamber and mingles with the ore therein.

A coal or oil furnace is indicated at 15, and fuel-oil pipes 16 are shown as opening downwardly through the top wall of the furnace. The products of combustion from these sources heat the ore-chamber to the temperature of incandescence (970 Fahrenheit) and pass into the latter at its open end and are thus caused to pass through the ore in order to reach the smoke-stack. Air must be excluded from the ore as far as possible, so as to prevent the formation of oxids and carbonates.

The gases arising from the products of combustion inter-mingling with the reducing-gas serve to decompose the minerals and reduce them to a spongy metallic form. The minerals are so reduced before the ores under gravity reach the discharge end of the reducing-chamber. The ores containing the metals in this spongy condition fall from the discharge end of the reducing-chamber into the lower end of the smoke-stack, Where the final concentration of the metal to metallic globules is effected. For this purpose fuel-oil pipes 17 are introduced into the bottom of the smoke-stack and the oil is burned with a limited supply of air for combustion, forming thereby hot reducing-gases. The gangue or matrix is slightly fused, and the mineral becomes collected in the form of small globular masses or shot. The metal being thus reduced is removed from the furnace, preferably through a door 18, forming the bottom of the stack, and is allowed to fall into a car or other suitable conveyer located under the furnace. Bycrushingand screening the metals may then be separated from the matrix.

In practice, While the products of combustion within the combustion-chamber are heating the reducing-chamber by contact with the outside thereof and in passing therethrough to the smoke-stack, the ore is supplied from the hopper. The reducing-chamber being gradually revolved the ores will by gravity travel toward the lower or discharge end. During their passage through this chamber they are by the action of the heat, coupled with the chemical action of the hydrogen gas and products of combustion, heated to the temperature of incandescence, there by decomposing the minerals and reducing them to a metallic spongy condition. In this state the metals leave the reducing-chamber and pass into the concentrating-chamber at the bottom of the smoke-stack. There the matrix is fused and the metals assume a globular or nugget-like form. Upon removal from this concentrating-chamber the metals and matrix by simple crushing and screening are readily separated.

It will be noted that but little labor is required, since the ores travel through therotary reducing-chamber by gravity and one passage thereof is sufficient to reduce the minerals in the ores to a metallic spongy condition, so that the final concentration of 'the metal is readily efiected by a high heat sufficient to fuse the matrix or gangne.

I claim as my invention 1. A furnace for reducing mineral in ore having a reducing-chamber, through which the ore is passed, means for heating the ore in such chamber to the temperature of incandescence, means for introducing a reducing-gas into such chamber, the products of said heating means intermingling with said reducing-gas Within such chamber in the presence of the ore therein for reducing the mineral in such ore to a metallic spongy condition, and means Within the furnace adjacent to the discharge end of the reducing-chamber for concentrating the minerals into metallic globular formation after they leave such chamber, as set forth.

2. A furnace for reducing mineral in ore, having a combustion-chamber and a smokestack, a rotary red ucing-chamber Within said combustion-chamber through which the ore is passed, means within said combustionchamber for heating the ore in such reducingchamber to the temperature of incandescence, the products of such heating means passing through such reducing-chamber to the stack, means for introducing a reducing-gas into such chamber during the rotation thereof for intermingling with the products of the heating means in the presence of the ore, and

means within the smoke-stack for concentrat-.

ing the minerals into metallic globular formation as they are discharged into such smoke-stack from the reducing-chamber, as set forth.

3. A furnace for reducing mineral in ore having a reducing-chamber through which the ore is passed, means for heating the ore in such chamber to the temperature of incandescence, means for introducing a reducing-, gas into such chamber, the products of said heating means intermingling with said reducing-gas within such chamber in the presence of the ore therein for reducing the mineral in such ore to a metallic spongy condition, a concentrating-chamber into which the ores are discharged after leaving the reducingchamber, and means for fusing the matrix or gangue in such concentrating-chamber, as set forth.

4. The combination with the furnace having a combustion-chamber and smoke-stack, of a rotary reducing-chamber opening at one end into said stack, the other end of said reducing-chamber beingopen to the combustion-chamber and forming a passage for the products of combustion, an ore-feeding hop: per opening into such'reducing-chamber, a perforated pipe extended longitudinally into said chamber and connected thereto, said pipe at one end extending axially from said chamber through a Wall of the furnace, a tank to which such pipe is connected, and gearing engaging said pipe for rotating the reducing-chamber, as set forth.

5. The combination with the furnace having a combustion-chamber and smoke-stack, of the inclined reducing-chamber extended longitudinally through the combustion-chamber and mounted at one end in the wall of the smoke-stack, into which latter it opens, the other end of said reducing-chamber being open to the combustion-chamber at a point near the end wall thereof, a stop-plate partly surrounding such open end, means within the combustion-chamber for heating the air in the reducing-chamber to the temperature of incandescence, a perforated pipe extended through said end wall and into the reducing- ICC ducing-gas into said reducing-chamber, such gas intermingling with the products of combustion within said reducing-chamber, means within said smoke-stack for fusing the matrix of the reduced metals and concentrating the metallic globules, and a door for withdrawing the metals aud matrix from such concentrating-chamber, as set forth.

.; In testimony whereof I have "signed this specification in the presence of two subscribing witnesses.

OLIVER B. DAWSON, Witnesses:

GRAFTON L. MoGILL, FRANCIS S. MAGUIRE. 

